Interpretive Summary: The GPFARM decision support system was developed to provide producers an integrated farm/ranch tool to help assist in strategic planning of their farms/ranches. GPFARM should enhance the decision making of producers by evaluating the economic, production, and environmental aspects of various management practices and cropping systems on each field, or scaling up to the entire farm/ranch. From initial surveys of producers, system requirements were quickly identified, including: the DSS must be 'easy' to set up, use, and run; it must be applicable to diverse farms/ranches across a broad region (initially westcentral Great Plains); and it must be able to accurately simulate plant growth and yield across the environmental conditions and management practices of the broad region. This necessitated that the plant growth model (PGM) not only be able to simulate many different crops that are, or potentially might, be grown, but also most information/data needed to use the DSS (e.g., driving variables, initial conditions, and particularly the model parameters) be readily available, if not supplied, to the user. Considering producers are the primary user, it was considered unreasonable to expect them to set or input all data and information required to run the science simulation model and DSS. This talk addresses selected problems and solutions related to parameterizing the PGM.

Technical Abstract:
The GPFARM decision support system was developed to provide producers an integrated farm/ranch tool to help assist in strategic planning of their farms/ranches. GPFARM should enhance the decision making of producers by evaluating the economic, production, and environmental aspects of various management practices and cropping systems on each field, or scaling up to the entire farm/ranch. From initial surveys of producers, system requirements were quickly identified, including: the DSS must be 'easy' to set up, use, and run; it must be applicable to diverse farms/ranches across a broad region (initially westcentral Great Plains); and it must be able to accurately simulate plant growth and yield across the environmental conditions and management practices of the broad region. This necessitated that the plant growth model (PGM) not only be able to simulate many different crops that are, or potentially might, be grown, but also most information/data needed to use the DSS (e.g., driving variables, initial conditions, and particularly the model parameters) be readily available, if not supplied, to the user. Considering producers are the primary user, it was considered unreasonable to expect them to set or input all data and information required to run the science simulation model and DSS. This talk addresses selected problems and solutions related to parameterizing the PGM.